Precautions For Link Dedicated Instructions - Mitsubishi Electric MELSEC-Q Series User Manual

10.2.2 Precautions for link dedicated instructions

The following describes precautions when using link dedicated instructions.
(1) Executing multiple link dedicated instructions simultaneously
(2) Executing link dedicated instructions to AnUCPU stations
When executing multiple link dedicated instructions simultaneously, make sure that the
channels for the instructions are not duplicated. Link dedicated instructions with the
same channel cannot be executed simultaneously. To use the same channel for
multiple link dedicated instructions, execute one after completion of another. The
completion status of the dedicated instruction can be checked by the completion device
of the dedicated instruction.
(a) Channel
A channel is an area of a network module where data handled by a link dedicated
instruction is stored. By using multiple channels, it is possible to simultaneously
access from the own station to other stations or concurrently read from and write
to the same network module.
(b) Number of channels
The Simple Motion module has 2 channels that can be used for link dedicated
instructions. By using 2 channels simultaneously, two instructions can be
executed at the same time.
(Note-1): For the REMFR/REMTO instruction, up to 32 channels can be used.
(c) Number of link dedicated instructions that can be simultaneously executed
Even when channels are not duplicated, do not simultaneously execute link
dedicated instructions exceeding 34.
If the number of instructions exceeds 34, execute the instructions one by one.
(d) Application example of channels
• Simultaneous access to other stations from the own station
Use a different own station channel for each request destination.
Channel 1: Write to station No.17
Channel 2: Write to station No.18
(a) Executing an instruction to AnUCPU stations
Never execute a Simple Motion module dedicated instruction to AnUCPU stations.
Doing so will cause "MAIN CPU DOWN" or "WDT ERROR", and may result in an
operation stop in the AnUCPU.
Chapter 10 DEDICATED INSTRUCTIONS
(Note-1)
Station No.0
(Own station)
WRITE
Channel 1
Channel 2
WRITE
10 - 5
Station No.17
(Other station)
Station No.18
(Other station)